This invention relates to sorters for collating sheets into sets and is particularly but not exclusively concerned with sorters suitable for use with or as part of an office reproduction machine.
Frequently, it is highly desirable to reproduce a plurality of copies of the same original document or information. Moreover, if several original documents are reproduced, it is desirable to produce a plurality of collated sets of copies. This may be achieved by the utilisation of a sorter. Generally the sorter comprises a plurality of bins wherein each bin is designed to collect one set of copies of the original document. A variety of sorters are known in the art. Most sorters used commercially with photocopiers comprise a plurality of tray members which are spaced apart and extend in an array, which may be horizontal as for example in U.S. Pat. Nos. 3,944,207 and 4,015,841, or vertical as in U.S. Pat. No. 3,977,667. Such sorters take various well known forms. There are travelling gate sorters as described for example in U.S. Pat. No. 3,414,254 in which sheets are conveyed by a sheet transport past the openings of a vertical array of bins and a movable gate or feed throat traverses across the bin openings for deflecting the sheets into the respective bins in turn. Another type has fixed bins and a deflector or gate associated with each bin; a sheet transport advances the copy sheets past the bin openings and the deflectors are actuated in turn to guide the sheets from the transport into the respective bins. Finally, in moving bin sorters such as described in U.S. Pat. Nos. 3,788,640 and 4,055,339, the bins themselves are indexed past a fixed feed throat. Within such class of sorters may be included rotary sorters having bins extending radially outwardly from an axis of rotation, as shown for example in U.S. Pat. No. 3,851,872. It is also known from U.S. Pat. No. 4,073,118 to have a fan-like array of bins indexed past a fixed feed throat.
For maximum compactness for a given capacity, the bins should preferably be completely filled. However, the capacity of the bins is limited by the space required over the stack for insertion of the final sheet. To alleviate this difficulty it is known from various of the above mentioned patents that the bin entrance openings of the respective bins may be selectively increased in size by relatively moving the bin plates defining the opening as a sheet is fed into it.
This invention is concerned with sorters of the moving bin type and in particular with a sorter such as shown in Xerox Disclosure Journal Vol. 1 No. 4 April 1976 Page 59 which comprises a plurality of sheet-receiving bins defined by an array of movable plates and means for indexing the input ends of the bin plates sequentially past a fixed feed throat to align the bin openings in turn with the feed throat, adjacent said bin plates being relatively movable apart and together for varying the sizes of the bin openings. No indexing means is described in that disclosure. Such a sorter is also disclosed in Japanese Published Application No. 53-79545 where a unidirectional indexing system includes a Geneva wheel which allows the bins to fall past the feed throat one at a time.